Greater Wellington Regional Council will introduce a new key performance indicator for drinking water, following revelations fluoride was switched off without anyone knowing.
An independent inquiry is underway to find out why Wellington Water stopped fluoridation last year at two plants supplying Upper Hutt, Porirua, and Wellington City residents.
The regional council owns the water treatment plant assets and Wellington Water manages them on its behalf.
Council chief executive Nigel Corry said Wellington Water was focused on the provision of safe drinking water as outlined in the council's long-term plan and the company's statement of intent.
Wellington Water complied with standards set by the country's water services regulator Taumata Arowai, he said.
"[This] focuses on bacteria and protozoal compliance rather than the promotion of health benefits such as the fluoridation of water."
But council chairman Daran Ponter told the Herald a new KPI for fluoridation will be introduced by the council, given the situation they have found themselves in.
"We need to know if the fluoride is being dosed properly or delivered at all."
Regional councillor Thomas Nash said it was important to fix the situation immediately.
"It's a major structural problem that councils haven't been systematically monitoring water providers on a wider set of public health metrics such as fluoridation, beyond disease prevention."
Nash said people expected drinking water to keep people healthy.
"If we are only monitoring disease prevention then we don't get a heads up about things like this where a key public health measure, fluoridation, has failed. That's unacceptable."
Corry gave an update on the situation that's been labelled "ridiculous" and "alarming" at a full council meeting yesterday.
He confirmed the council was only advised by Wellington Water in March that fluoride had been turned off last year.
Corry said the council would wait for the inquiry's findings to decide if any further investigation was necessary into who knew what and when.
Terms of reference for the inquiry were released this week. It will focus on why customers, Wellington Water's Board, and the Wellington Water Committee were not told about the fluoride failure in a timely and accurate manner.
At the meeting, councillors committed in principle to approve funding to restore fluoride to the water supply and get new equipment as soon as possible, Corry said.
"The next steps are for Wellington Water to provide further details to finalise the funding. The level of funding is subject to commercial sensitivities and will be released at a later date."
Last month Wellington Water called in divers to assess the damage to fluoride facilities in a reservoir the size of two Olympic swimming pools.
The company is also looking at a fluoride system that can be housed in a shipping container because the existing concrete ceiling at one of the plants has deteriorated so much that workers cannot safely access the fluoride room.